On Mon, 8 May 2017 15:43:33 -0500 Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > Ok, so just to clarify. Is there a bug in the ftrace stack tracer in > the following situation? > > 1. RCU isn't watching > 2. An NMI hits > 3. ist_enter() calls into the ftrace stack tracer, before > rcu_nmi_enter() is called, so RCU isn't watching yet No, because in the ftrace stack tracer there's: if (in_nmi()) return; At the very beginning. -- Steve > 4. The ftrace stack tracer calls rcu_irq_enter(), which has no effect, > so RCU still isn't watching > 5. Hilarity ensues in the ftrace stack tracer > -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
